Brewster Windows are designed such that at Brewster’s angle (55.57°), s-polarized light will be partially reflected, whereas loss of p-polarised light is minimised. When placed within laser cavities, Brewster windows will cause the laser output to product linearly p-polarised light.

Brewster windows can be fabricated with different substrates namely BK7, UVFS, Sapphire, CaF2, ZnSe, etc.